Behavioral changes in adult rats after prenatal exposures to complex, weak magnetic fields

More than 100 adult male and female albino Wistar rats that had been exposed during their entire prenatal development to one of two patterns of magnetic fields and one of four intensities (reference: 5 to 20 nT; low: 30 to 50 nT; medium: 90 to 580 nT; high: 590 nT to 1.2 microT) were tested for their capacity for two forms of classical conditioning. The rats exposed for 10 sec every 50 sec to a field composed of successive 200 msec sequences of several different patterns known to produce physiological effects exhibited significantly more intense conditioned fear and taste aversion than those exposed continuously to a single frequency-modulated pattern. The behavioral differences, relative to the reference group ("controls"), were greatest for rats exposed to the 30 to 50 nT or 90 to 580 nT (low to medium intensities) for both patterns of fields. These results suggest that prenatal exposure to physiologically-patterned magnetic fields within a specific "window" of intensities that overlap with values found in many human habitats may produce long-term changes in behaviors.